Internal combustion engine



May 23, 1933.

L. M. 'wooLsoN INTERNAL coM'BUsTI'oN 'ENGINE Filed June 5, 1927 2 Sheets-Sheet 'l L.: DNEL HI NUDL 50N.

Mai' 23; 1933. L. M. wooLsoN 1,910,375

INTERNAL COMBUSTIONr ENGINE Filed Jun@ 3, 1927 sheets-sheet -2 JZ v' l j 44 .sz 4@ l supplied to the moving parts of an engine.

Patented Maly 23, 1933 res PATENT oem-CE LIONEL M. WOOLSON, 0F DETROIT, MICHIGAN, ASSIGNOR TO PACKARD MOTOR CAB COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN INTERNAL COMBUSTION ENGINE Application filed June 3,

This invention relates to internal combustion engines, and more particularly to lubricating mechanisms therefor.

It is found desirable to cool the lubricant supplied to the bearings of internal combustion engines, particularly airplane engines, because such engines are likely to be operated at maximum load and at' high speed over long periods of time. It is also desirable to automatically maintain a constant supply of oil to the engine crankcase and to automatically replenish this supply as it is diminished during operation in order that long non-stop flights may be made.

The supply of lubricant may be maintained by a make-up pump connected to an oil reservoir, and the level of the oil may be determined by a standpipe having an inlet opening in the crankcase, and connected to a scavenging pump having an outlet conduit extending to an oil reservoir external to the crankcase. The scavenging and make-v up pumps are of small capacit since they are'required to supply only sma l quantities,

.hence a pressure pump of relatively large capacity must be provided. Heretofore, when oil coolers have been provided, it has been the practice to locate them externally of the engine crankcase, and to circulate the oil supplied to the bearings through the cooler, hence large, heavy, cumbersome pipes of considerable length, have been required. Such pipes have the great disadvantage, particularly on airplane engines, that they increase the weight of the engine and the space occupiedthereby and also are liable to break and cut oil' the engine oil supply.

An object of the present invention. is to lubricate the moving parts of an interna] combustion engine.

A specific object is to cool the. lubricant An additional object is to reduce the size 'and weight and to otherwise simplify the 1927. Serial No. 196,157.

lubricating mechanism of an internal combustion engine.

A feature of the invention is a lubricant cooler located in the crankcase of an engine closely adjacent to the oil pump and parts to be lubricated.

Another feature is an arrangement of oil cooling and oil pumpin facilities adapted to maintain a supply o? cool oil at a constant level in the crankcase of an internal combustion engine.

Other features and objects of the invention will appear from the following description taken in connection with the accompanying drawings, wherein like reference characters have been used to indicate like parts and wherein:

Fig: 1 is a side elevation, partly in section, of an internalcombustion engine embodying this invention;

Fig. 2 is a fragmentary end view in elevation, partly in section ofthe engine of Fig. 1;

Fig. 3 is a .view in section on line 3-3 of Fio. 1, and

Fig. 4 is a view in section on line 4 4 of Fig. 1.

The engine shown in Fig. 1 includes a cylinder block 10, crankcase 11, crankshaft 12, camshaft 13, and driving shaft 14, and connectin rods 14 only one of which is shown, aapted to connect with respective pistons not shown. The crankcase contains a horizontal filtering screen 11', an oil cooler 15, and associated oil pumps, including a combined scavenging and make-up pump ,16,l and a pressure pump 17; the pump 16 being connected to an oil tank or reservoir 18, external to the crankcase.

The crankshaft 12 is journaled in suitable bearings 19 in the cylinder block 10 and the camshaft 13 is mounted in bearings 20 only one of which is shown. The right hand end of the crankshaft is provided with a bevel Y gear 21 meshed with agear 22 on the end of the vertical shaft 14, and also meshed any` suitable manner; for

lwith a second ond shaft 24.

f and the several gears just mentioned require shaft 12 is provided with ducts 12 to communicate during eachA revolution *with adapted to supply oil lubrication and for this 'purpose ducts 27 extending to thevarious crankshaftbearings and a ducty 28 extendin bearin s are provided an are connected to a main uct 29 extending to the outlet port ofy the oil ypressure pump v17. yThe crankadapted to the camshaft the respective ducts Theducts 12 eX- tend up the crank with recesses 12 in the cranks which are to the several connect- Iing rod bearings through radial ducts 12a.

' The roil ducts and the oil pumps 16 and 17 are shown more or less diagrammatically in IBG order to simplify the explanation of the ,inn vention. The pumps 16 and 17 maybe or*- dinary gear pumps or any other ysuitable type. The inlet port of thepump 17 is connected by a 'duct 30 and a conduit 31 to the oil cooler 15. A duct 62 normally closed by a spring pressed relief valve 63 is adapted to communicate upon opening of the valve with a duct 64 extending to the inside of the crankcase.

The oil cooler, which is positioned substantially in the middle of the crankcase, in cludes a casing 33 having a circumferential row`of inlet openings 34 near the bottom thereof. The upper and lower ends of the casing are closed by circular 36 respectively', Figs. 3 and 4, having a plurality of holes or perforations in which are inserted the opposite ends of a corresponding pluralit of pipes or flues 37'. The

lates 35 an 36 are joined to the casing and to the flues 37 by welding or in any other suitable manner so as to provide an oil and water tight closure. An. outer, circular endplate 38 is positioned at the upper end of the casing and is separated somewhat from the plate 35 to rovide a passa e for water between the ues on either side of the bale 41. The plate 38 is likewise attached-by an oil and water tight joint to the casing and is provided with a hole at its center through which. the pipe 32 passes. The joint between the plate 38 and the pipe 32 is rendered oil and water tight in any suitable manner for example by welding. A solid bottom plate 40 is attached to the casing 33 at the lower end thereof to provide a water and oil tight closure and is spaced a distance plates 35 and bevel and camshaft bearings arms and communicate f pipe 55 in the crankcase, v stand pipe being located oil tank 18.

from the end yplate 36 yto allow for the passage of water into the iues 37 on one side of the baffle 41 and out of the 'flues on the other side thereof. yThe bafe 41 consists of an integral diametral flange on the plate 40 which 'extends entirely engages at its upper edge the bottom of the plate 36 and also the bottom of the cylindrical baille 42 which is inserted through hole lin the center of this plate and welde or otherwise attached thereto to provide an oil and water tight joint. The plate 40 includes a water inlet port k43 connected to an inlet conduit 44 and a water outlet port 45 connectedkto an outlet conduit 46. The conduits 44 and 46 extend to respective outlet and inlet'portsf47 and 48 in a main cooling waterfsupply line`49, Fig. 2, including a water pump- 50 and a conventional radiator, not shown, adapted to supply cooling water by meansof conduits 51 and 52 to the water jackets of the engine cylinders. Inside of the pipe' 49 is an integral tube 53 having a restricted kneck portion 54 constituting n a Venturi tube. Y y

The scavenging portion'of the oil pump 16 includes an inlet port connected to a stand as near as possible to the middle of the crankcase and at the level at `which itis desired to maintain'the oil'inv the crankcase. An outlet port of the pump 16 is connected by aconduit 56 to an inlet opening 57 at the top of a reservoir or The make-up portion of the pum includes an inlet port connected by a conduit 59 to an outlet opening 60 in the bottom of the, tank 18 and also includes an outlet port connected to a pipe 61 extending vertically adjacent to the shaft 14, its upper end being open and above the gear 26. An overflow conduit 67 has one endconnected to a port 68 4at'the top ofthe tank 18 and its other end connected to a p ort 69 opening into the drive shaft housing 70, whereby foam and excess oil may be drained into the crankcase, and air may be admitted and expelled from the tank as the oil level therein rises or falls. The crankcase is of course open to atmospheric pressure via the usual filling conduit not shown. The tank 18 is provided with an oil level gauge 18 which may be of the boiler gauge type, for enabling the oil level to be observed at all times.

In the operation of the cooling and lubricating system of this invention, oil from the crankcase 11 enters the casing 33 of the cooler 15 through the ports 34 and passes between the flues or pipes 37 as indicated by the arrows in Fig. 3. Under the suction of the pump 17, the oil in the cooler Hows through the outlet pipe 32, the direction of iow being determined by the cylindrical baffle 42, which serves to eii'ect an even distribution of the 011 through the cooler, whereby the' opening of the across the plate and most eiiicient operation of the cooler is secured. The oil passes through the conduit 31 and the duct 30 into the pump 17. From the outlet port of this pump, the oil is forced' up throug the duct 29 into the ducts 27 and 28, and thence tothe bearings 19 and 20, and via the ducts 12', 12 and 12a to the connecting rod bearings. The pressure of oil supplied by the pump 17 is determined by the relief valve 63 in accordance with the tension of the s ring which may be adjusted by turning the threaded plug 66. When the pressure of oil exceeds the force of the spring 65, the valve 63 opens and the excess oil passes out through the duct 64 which empties into the crankcase.

The make-up portion of the pump 16 receives oil from the tank 18, via conduit .59, and pumps this oil through conduit 61. This fresh oil flows down over the camshaft and drivin shaft gears into the crankcase and replenlshes the oil therein. The make-up pump is preferably designed to supply oil approximately at the rate at which it is consumed or in a volume slightly greater than this rate. When the oil in the crankcase rises above the opening of the stand pipe 55 it is drawn through .this pipe into the scavenging port-ion of pump 16 and is forced back vla conduit 56 into the supply tank 18. The scavenging pump preferably has a slightly greater capacity than the make-up pump so that should the make-up pump supply oil faster than it is consumed the oil 1n the crankcase will nevertheless always be maintained at the level of the opening'of the stand pipe.

The oil in the crankcase becomes heated by contact .with the bearings and other hot parts of the engine and this oil is cooled, before being re-supplied to the bearings, by contact with the fines 37 of the cooler 15, in which water is circulated as follows: Referring to Fig. 2, the water flowing through the main engine cooling line 49, under the action of pump 50, passes through the Venturi tube 53, and 1n accordance with the lwell known action of such tubes, a difference in pressure is produced between the branch outlet opening 47 and the branch inlet opening 48, such that water is forced out of the Outlet opening and is` drawn in through the inlet opening. The outlet opening 47 communicates wlth the conduit 444, whereas the inlet opening communicates with the conduit 46. Water flowing from the outlet openingr passes through conduit 44 into the inlet port 43 of the cooler and is Vdirected by the balile 41 up through the lues at one side of the baille and down through the filles on'the opposite side there-l of, out through the outlet port 45 and, via the conduit 46, to the inlet port 48 of the Venturi tube, where it Vmerges with the stream in the main line. A sufiicient volume of water is forced through the` flues to maintain the oil in the cooler at a suitable operating temperature, the volume being determined by the size ofthe conduits, the Venturi tube and the water pump, and the rate of flow in the water in the main line.

By virtue ofthe fact that the cooler 15 is positioned within the crankcase 11 closely .adjacent to the pump 17 and the engine lparts to be lubricated, the conduit 31 connecting this cooler to the pressure pump 17 may be relatively short and no additional conduit connecting the crankcase to the inlet openings of the cooler is required, hence the Weight of the mechanism and the space occupied thereby are reduced so that a compact structure results and the danger of `failure of the oil supply to the bearings caused by breakage of the pipes is minimized. Moreover, in this location, the oil in the cooler is quickly warmed in cold weather' by heat transmitted thereto from the combustion chamber by conduction through the metal of the engine and also by the 'water circulation through the ues of the Vcooler which is warmed by passage through the water jackets of the `cylinders and is not reduced to a low temperature in -the radiator, andthe danger of an inadequate oil supply when startin'g cold, because weight or added space is involved. Theoil tank, 18 may therefore be located at a distance from the engine in a position free from material vibration and Where the oil supply can be constantly observed. The tank 18 may, of course, if desired, be mounted on the engine itself.

The present invention has the further advantage that an airplane engine constituting a complete operative unit is provided capable of operation for a considerable period of time without the necessity of manually adding oil.

The oil cooler has been shown preferably connected to the intake line of the force pump, but instead it -may also be included in the intake line of either one of. the other pumps. p

Although this invention has been dcscribed in connection with certain specific embodiments, the principles involved are susceptible of other applications that vxiil readily occur'to persons skilled in the art,

hence the invention is to be limited only as indicated by the scope of the appendedY pump for supplying oil to moving parts of said engine, and an'oil cooling device in the crankcase through which oil is drawn by said force pump from the crankcase.

2. The combination with an internal combustion engine including a cylinder block, a crankcase connected to said cylinder block, a crankshaft enclosed by said crankcase, a camshaft and a driving connection between said crankshaft and said camshaft, of means for supplying lubricating oil to said crank shaft and camshaft and for maintaining a substantially constant level of oil in said crankcase comprising an oil cooling device positioned in said crankcase, a pressure ump connected between said device and said shafts for supplying lubricating oil thereto, and a combined scavenging and make-up pump havinga capacity materially less than said force pump, an oil reservoir external to said crankcase and conduits connecting said make-up and scavenging pumps to the bottom and top respectively of said reservoir, a stand pipe in said crankcase connected to said scavenging pump and an outlet conduit fromsaid make-up pumps, said conduit having an outlet opening ositioned above said camshaft and at a evel above the level of oil of said reservoir.

3. A lubricating system for internal com bustion engines, comprising acrankcase arranged to receive oil draining from lubricated parts of the engine, an oil cooler Within the engine crankcase through which oil passes, a pump within the engine, and connections Within the engine leading from the pump to the cooler and the engine parts ref quiring lubrication, said pump circulating oil from the crankcase through the cooler to the engine parts requiring lubrication.

4. A lubricating system for internal combustion engines, comprising a crankcase arranged to receive oil draining from lubricated engine parts, an inclosed oil cooler submerged in and in open communication with the oil in the c'rankcase, means for maintaining a predetermined level of oil in the crankcase, conduit means within the engine leading from the cooler to the engine parts to be lubricated, a pump Within the engine for conducting oil from the cooler through the conduit means, and a pressure relief for' the conduit means.

5. A lubricating system for internal com bustion engines comprising a crankcase arranged to receive oil draining from lubricated engine parts, means for conducting oil from the crankcase to some of the engine parts to be lubricated, a reservoir, means for conductin oil in excess of a predetermined quantity rom the crankcase to the reservoir, and means for conducting oil from the reservoir to other of the engine parts to be lubricated.

6. A lubricating system .for internal combustion engines comprising a crankcase arranged to receive oil draining from lubricated engine parts, means for conducting oil from the crankcase to some of the engine parts to be lubricated, a reservoir, means for conducting oil from the crankcase in excess of a predetermined `quantity to the reservoir, means for conducting oil from the reservoir to other of the engine parts to be lubricated,

and an overflow connection from the reser voir to the engine crankcase.

7. A lubricating system of the Wet sump type for internal combustion engines, comprising a crankcase arranged to receive and contain oil draining from lubricated engine parts, a reservoir, conduit means for conducting oil in excess of a predetermined quantity from the crankcase to the reservoir, conduit means 'for conducting oil from the reservoir to engine parts to be lubricated, and a conduit extending from the reservoir to the crankcase, said conduit being connected with the upper portion of the reservoir.

8. A lubricating system for internal combustion engines comprising a crankcase arranged to receive oil draining from lubricated parts of the engine, means for conducting oil from the crankcase to some of the engine parts to be lubricated, a reservoir connected with the crankcase, and means for conducting oil to the reservoir from the crankcase and from the reservoir to other parts of the engine to be lubricated.

9. A lubricating system for internal combustion engines comprising a crank case arrangedto receive oil draining from lubricated parts of the engine, a surplus oil res ervoir, a pressure pump adapted to circulate oil from the crank case to some of the points of lubrication, a scavenglng pump adapted to force surplus oil from the crank case to said reservoir, and a make-up pump to force oil from the reservoir to one of the points of lubrication, said pressure pump having a large capacity relative to the scavenging and make-up pumps.

10. A lubricating system for internal combustion engines comprising a crank case arranged to receive oil draining from lubricated parts of the engine, a surplus oil reservoir, a pressure pump adapted to circulate oil from the crank case to some of the points of lubrication, a scavenging pump adapted to force surplus oil from the crank case to said reservoir, a stand pipe to determine the oil to the 0001er, means Within the engine circulation of the scavengin pum), and a. make-up pump .t0 supply oi at a ow rate from the reservoir to a high point of lubrication on the engine.

11. An oiling system of the Wet sump type, for an internal combustion engine, comrising engine cooling fluid means within t e engine to cool the oil, means Within the engine including a pump to ur e cooled oil towards the engine parts to be 1u ricated, means Within the engine for conducting used tending to add an excess of oil to the sump, and means within the engine tending to maintain a constant level of oil in the sump.

In testimony whereof I aiiix my signature.

LIONEL M. 'WOOLSON 

